Compressor intake-muffler



March 30, 1 926.

w. RAYMOND COMPRESSOR INTAKE MUFFLER Filed Dec. 5, 1924 .m Rev Ew n Wand,

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Patented Mar. 30, 1926.

UNITED STATES PATENT OFFICE.

WARD RAYMOND, OF EASTON, PENNSYLVANIA, ASSIGNOR TO PENNSYLVANIA PUMP & COMPRESSOR COMPANY, OF EASTON, PENNSYLVANIA, A CORPORATION OF rnn'nsyrvmm.

comrnnssoa INTAKE'MUITLER.

A Application filcd December 3, 1924. Serial No. 753,652.

To all whom it may concern:

Be it known that I, WARD RAYMOND, a citizen of the United States, residing at Easton, in the county of Northampton and State of Pennsylvania, have invented certain new and useful Improvements in Compressor Intake Mufllers, of which the following is a specification.

This invention relates to compressors and in particular to an improved form of intake therefor.

A principal object of the present invention is to provide means for eliminating or materially mufiling the suction noises of a compressor. v

A feature of construction which enables me to accomplish the above named object is that the intake is provided with a terminal conduit, the passage for the fluid passing 2 through it being of Venturi form; that is,

the intake passage is restricted in a part of the intake conduit, the restricted part merging into the full intake passage by portions slowly increasing in cross section.

' Another object of the invention is to pro- .vide means in the intake to uniformly in-e crease the velocity of the fluid admitted to the compressor materially but with a mini mum of frictional losses and, after maintaining the velocity of the fluid at this increased speed, slowly reduce the velocity again to normal.

I Another feature which is advantageous is thatthe restricted portions of the intake are proportioned to materially increase the velocity of the fluid being compressed so that the-noises passing out throughithe intake will' be greatly muflled. It will be appreciated that should the velocity of the entering fluid be greater than the velocity of sound traveling through that fluid, the sound waves would be prevented from back out through the intake, and while it is usually not advisable to increase the velocity of the fluid to this extent, it is permissible by the use of proper design of entrance and exhaust passage to raise the velocity of the fluid to such-an extent that the noise is reduced to a satisfactory point.

Another principal ob ect of'the invention is to form'the intake of a compressor with a constant and freely open passage for the fluid admitted without baflies or vanes and assing which will admit the fluid to the compressor with a minimum of friction losses and pressure reduction.

Also, it is an object to provide a hood and screen on the free end of the intake to-circlude foreign substances, these being mounted at the outer end of the intake and attached thereto in a manner to permit ample passage of fluid into the restricted passages of the intake.

lVith these and other objects in view, my invention consists in the features of construction and operation set forth in the following specification and illustrated in the accompanying drawing.

In the accompanying drawing annexed hereto and forming, a part of this specificaticn; I have shown my invention embodied in a powerdriven air compressor of relatively small size, but it will be understood that the invention can be otherwise embodied and that the drawings are not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawing: Figure 1 isa side elevation of a compressor provided with the improved intake forming the subject matter of the present application; and

Fig. 2 is a longitudinal sectional view of the intake withvhood and screen attached. In the above mentioned drawing, I have shown but one embodiment of the invention which is now thought to be preferable, "but it is to be understood'that' changes and modifications may be made within the scope of the appended claims without' departing from the spirit of the invention. Briefly, and in its broadest aspect, my invention comprises the following principal parts: first, an intake pipe; second, a conduit connected thereto and having a passage for the entering fluid of restricted area; third, a hood over the free end of this conconduit'; and fourth, a screen secured to 100 the conduit and hood to cover an open space between the hood and conduit.

Referring more in detail to the figures I provide the intake pipe 10 of a compressor 11 with a conduit 12 secured at its free end. 1

' tional area.

10 is provided with an elbow 13 to which is threaded the conduit 12. Secured at the free end of the conduit 12is a hood 1?: covering the open end of the conduit 12. This is secured to the conduitby long bolts .15 passing through sleeves 16 between theihood 14 and conduit 12 and threaded into, the end surface of the conduit. Surrounding the sleeves 16 supporting the hood 12 is anbpen' full area but is rapidly reduced in area by the bell shaped opening 22. For a portion *of the intermediate part of the conduit 12,

the area of the passage is restricted. materiallyas shown at 23, this reduction in area being sufficient to very greatly increase the velocity of the fluid being admitted. During normal operation of the compressor 11,

the highvelocity of the fluid through this portion 23 of the intake conduit 12 opposes the velocity of sound passing back out of the conduit so that the sound of the compressor valves and of fluid passing through them will be materially muffled or eliminated.

From the opposite end of the restricted area 23, thepassage 11 increases in diameter gradually butuniformly due to the curved form 24 of the inner wallof the conduit 12. At the extreme inner end of theconduit 12, the area is increased to the full diameterof the intake pipe 10. at which point screw threads 25 are provided forattaching the conduit 12 to the-elbow 13. Anothervconvenient way of attaching the conduit to the intake isby providing it with suitable guiding ribs 26 so that when inserted in the open end of the conduit, which inthat case is usually standard commercial steel "pipe, it

may be guided and retained in position.

What I claim is: 1. A compressor, an intake therefor,'a conduit forming a part of said intake and having a restricted passage therethrough of material-length to materially increase the velocity of the fluid entering the compressor, and velocity changing passa es of varying cross section on opposite si es of said restricted passage, the restricted andvelocity changing passages being circular in cross section throughouttheir length.-

2. A compressor, an intake therefor, a conduit forming a part of said intake and havinga uniformly-restricted passage formed in its intermediate portions of material length, said restricted passage being grad- .ually enlarged toa full opening at the inner end ofthe conduit-said passage being circular in cross section throughout its length.

3. A compressor, an intake therefor, a conduit forming a part of said intake-and having a bell-mouthed opening at its outer end, a uniformly restricted passage of material length through its intermediate portions, and argrad ially expanding passage from the restricted passage to the compressor intake,

through said restricted passage and, reduced again to normal, and means to attach said conduit to the intake of a compressor.

5. A compressor, an intake therefor, a conduit forming a part of said intake and having a'hood spaced therefrom and secured to the free end of the conduit, said conduit having a restricted fluid passage of varying area, a mid-portion thereof being uniformly restricted for a material length, said pas sage being circular in cross section throughout its length, and means to attach the conduit to the compressor intake. 6. A compressor, an intake therefor, a conduit forming a part of said intake having a hood spaced therefrom and secured to the free end of the conduit, a midortion of the passage being uniformly. restr cted for a material length, velocity changing passages on opposite sides of said uniformly restrict-e passage, said passages being circular in cross section throughout their length, a screen-interposed between the hood and conduit, and means to attach the screen to the conduit. 1 p

In testimony whereof, I hereto affix my signature. WARD RAYMOND. 

